UKVIKW OK 11 IK HOOK 29. '{ 



I'J. Kxpiaiii tlie tlireo proat subjects with wbicli a^jriculture 

 dcnls. 



IJ. Is n^jrjcultiire n Bcienoo or an aitt 



It will lit> iiotictHl that tin- Itody ot" the hook 

 is (li\i(l»Ml into thi«M' co-ordiiiat*' parts: the soil^ 

 the plant, the animal. Tin's*' n'pn'st'iit tlu' thrrt' 

 pi-fat t'uiuhimcntals on which tlic siicccssliil j>rac- 

 tic'c ol' aiificiiltiii-t' <h'jMMiiN. A coiujij.-tf treatise 

 on ai^ricultiire would iiicliKh- a division thtit 

 would liavo to do with the -^k'neral ••eonoinic 

 principles that underlie tlu' husiness, and another 

 on tiie social relations; hut the insertion of tliis 

 discussion would carry the jiresent vohune ([tiito 

 hi'vond its limits of usefulness as an elementary 

 text-book. 



PART I. Till-: SOIL 



The soil is considered in several a>pti i-. It 

 is important to state at the outset that the pri- 

 mary consideration is not the j)lant-t"ood alone 

 in tlie soil, Imt the pliysical ciiara<-teristics as 

 well. In the ohler books it was jMistoinary to 

 place most of tlie stress on the ehemienl eon- 

 tent of tlie s<^il. This was because njrrieulturni 

 chemistry was the first of the natural scienci'S 

 to make cjreat eontributions to the a«lvain'ement 

 of nirriculturnl knowlodjr^. It is now under- 

 stood that the physical eonstitiition of the soil 

 is as important as its chemical < -^'itution; it 



